The Centers for Disease Control announced Monday that there were 21 new cases of measles in the most recent recorded week, bringing the total number to 1,203 confirmed cases.
In early May, there were 60 new cases in a week, and in late April, that number jumped to 78 cases in one week. There were 71 new cases the week before that. The numbers through May 17 showed an increase of 41 cases from the prior report.
The number of cases this year already reached the highest number since measles was declared eliminated in the country in 2000.
The 1,203 figure also means it is the greatest number of measles cases in the U.S. since 1992, according to the CDC. There are now 30 states that have confirmed cases, with recent additions including Ohio and Alaska.
There are six ongoing outbreaks, where three or more cases are in effect, which is down from higher numbers earlier this year.
The outbreaks still remain in New York's Rockland and Wyoming Counties, New York City, Washington state, Los Angeles County in California, and El Paso, Texas.
More than three quarters of the cases were linked to outbreaks in New York, the CDC reported. Those outbreaks, including the ones in Rockland County and New York City, started in 2018 and carried through to the present.
According to the Rockland County health department website, the outbreak there was tied to 296 cases, and in New York City there have been 653 confirmed cases, the city's health website states.
(MORE: Staggering number of measles cases in US just part of 300% global uptick )The CDC reported that of the 1,203 confirmed cases, 124 people were hospitalized and 64 people reported having complications that included pneumonia and encephalitis.
The majority of cases were reported to have infected people who had not been vaccinated against the disease.